For most small businesses, late payment of invoices by other businesses is a constant irritant, and sometimes worse. Companies are expected to deliver goods and services to the perfect satisfaction of the customer, who then pays the invoice in his own time. That leads to cash-flow problems and often to a knock-on effect, as your own bills go unpaid - putting other small businesses into difficulties.

According to estimates, one invoice in three is paid late. Belgium is reckoned to be one of the worst offenders in Europe on this score, and some estimates suggest as many as 2,000 bankruptcies a year can be attributed to late payment of invoices.

Organisations representing small businesses have tried for years to make penalty clauses more widespread, against the opposition of large companies, who often use late payment as a deliberate strategy. But now the website ikki.be may have come up with the answer: an invoice that bursts into heart-wrenching tears.

Ikki, a sort of marketplace site where freelancers can advertise themselves and look for work, is offering two free music chips for every new registration. Just attach the chip to your next follow-up invoice and, when it's opened, your client won't be able to resist the sounds of sobbing that follows.

The action is meant to be tongue-in-cheek, but the demand is clearly there; no sooner had the campaign started than it ground to a halt, as demand outstripped supply. People who had requested chips were asked to be patient until new stocks could be sent.

In the meantime, the site also allows you to make up a weeping telephone message. It's enough to melt even the steeliest corporate heart.

www.ikki.be